taxonomies-dropdown-filtering-for-post-types.php

<?php

function lt_admin_show_taxonomies_dropdowns() {
	if ( 'lt_product' != get_current_screen()->post_type )
		return;

	$taxonomies = get_taxonomies( array(
		'object_type' => array( 'lt_product' )
	), 'objects' );

	foreach ( $taxonomies as $t => $details )
		wp_dropdown_categories( array(
			'show_option_all' => sprintf( __( 'View %s' ), $details->labels->all_items ),
			'hide_empty' => 0,
			'hierarchical' => 1,
			'show_count' => 0,
			'orderby' => 'name',
			'selected' => isset( $GLOBALS[ $t ] ) ? $GLOBALS[ $t ] : '0',
			'taxonomy' => $t,
			'name' => $t,
			'walker' => new Lateltin_Walker_Taxonomies_Dropdown,
		) );
}
add_action( 'restrict_manage_posts', 'lt_admin_show_taxonomies_dropdowns' );

/**
 * Custom walker that echos slugs instead of IDs
 *
 * @since 1.0
 */
class Lateltin_Walker_Taxonomies_Dropdown extends Walker {
	var $tree_type = 'category';
	var $db_fields = array(
		'parent' => 'parent',
		'id'	 => 'term_id'
	);

	/**
	 * @see Walker::start_el()
	 * @since 2.1.0
	 *
	 * @param string $output Passed by reference. Used to append additional content.
	 * @param object $category Category data object.
	 * @param int $depth Depth of category. Used for padding.
	 * @param array $args Uses 'selected' and 'show_count' keys, if they exist.
	 */
	function start_el( &$output, $category, $depth, $args, $id = 0 ) {
		$pad = str_repeat( '&nbsp;', $depth * 3 );

		$cat_name = apply_filters( 'list_cats', $category->name, $category );
		$output .= "\t<option class=\"level-$depth\" value=\"".$category->slug."\"";

		if ( $category->slug == $args['selected'] )
			$output .= ' selected="selected"';
		$output .= '>';
		$output .= $pad.$cat_name;
		
		if ( $args['show_count'] )
			$output .= '&nbsp;&nbsp;('. $category->count .')';
		$output .= "</option>\n";
	}
}